Reliable, Reusable Ada Components for Constructing Large, Distributed Multi-Task Networks: Network Architecture Series (NSA)
Walker Royce · 1989
This paper will introduce the key concepts of TRW's Reusable Message Based Design Software (Network Architecture Services-NAS) which has proven to be key to the CCPDS-R project's progress to date. The NAS software and supporting tools have provided the CCPDS-R Project team with reliable, powerful building blocks that have been integrated into extensive demonstrations to validate the critical design approaches. The CCPDS-R PDR Demonstration consisted of 130 Ada tasks interconnected via 450 different task to task interfaces, executing in a network of 3 VAX nodes. The extensive reuse of NAS software building blocks and Ada generics resulted in the translation of 120,000 Ada Source lines into over 2 million lines of executable machine language instructions. This paper describes the message based design techniques which drove us to the development of NAS, the capabilities and components inherent in the NAS product, and the CCPDS-R experience in using NAS in a stringent real time command and control environment.